1. Field of the Invention
The present invention relates to logic circuitry, and more particularly to EXCLUSIVE OR and EXCLUSIVE NOR gates.
2. Description of Related Art
EXCLUSIVE OR logic gates are used in a variety of logic circuits including arithmetic function generators such as array multipliers, arithmetic logic units and the like. EXCLUSIVE NOR is a related function which may be produced by inverting the output of an EXCLUSIVE OR gate. Alternatively, a separate logic gate can be utilized to provide the EXCLUSIVE NOR function.
To increase the speed of operation, many logic circuits have a parallel structure in which both EXCLUSIVE OR and EXCLUSIVE NOR gates operate simultaneously to provide the EXCLUSIVE OR and EXCLUSIVE NOR function outputs at the same time. However, this parallel structure generally acquires more space. As a consequence, the increase in speed may cause the overall logic circuit to be larger or to have a reduced number of functions.